This invention relates to an exercise machine employing principles designed to strengthen muscles without producing destructive forces on the bones, ligaments, and other body parts during exercise.
Typically, exercise machines designed to provide a subject the means to strengthen muscles employ some form of resistance the subject must overcome in order to complete the movement of the exercise. The forces used to generate this resistance also produce forces which tend to compress the joints and ligaments. This compression could result in injury to a subject. For example the forces used to generate this resistance as they apply to the back, can also produce a force downward on the spine which tends to compress the spine and disks subjecting this area to possible injury.
In many parts of the body as the muscles increase in strength, so to do the corresponding ligaments and bones. However, some bones and muscles can become injured if forces encountered during exercise are not correctly directed.
A number of machines have been devised to increase the strength of lower back muscles. U.S. Pat. Nos. 5,256,126, 5,142,944, 5,110,121, 5,100,131 and 5,070,863 describe machines that requires a subject to overcome a force with both parallel and perpendicular components on the back in a seated position. The subject is required to move part of the machine a certain distance.
U.S. Pat. No. 5,256,126 employs a barrier and seat. The subject is bent over seated in a chair at some fixed angle. Said subject exerts force on a barrier by pushing the barrier away when seated. The barrier is positioned in back of the subject. No attempt is made to restrict the compressive forces on the back. Said subject is required to exert a force directed upward and outward. The reactionary force has components directed downward thus subjecting the spine to possible injury by compressing the spine.
In U.S. Pat. No. 5,142,944 the subject is seated and has to overcome a force with both parallel and perpendicular components on the back. The parallel forces are directed in such a manner that would predispose a subject to injury by the compression of said subjects spine and back.
U.S. Pat. No. 5,110,121 consists of an exercise machine which requires the subject to be positioned in a chair. Contacts from said machine produce a force on the subject which tends to compress said subjects back.
U.S. Pat. No. 5,100,131 requires a subject to be positioned on a seat in such a manner that the restraints of the apparatus provide a resistive force on said subject. No attempt is made to reduce the compressive forces. Such forces as described will tend to compress said subjects back.
U.S. Pat. No. 5,070,863 describes a back exercise apparatus consisting of a chair and restraint. Here again, no attempt is made to reduce the compressive forces.
U.S. Pat. No. 5,108,090 describes a back exercising apparatus designed "To expand and contract to stretch the user's paraspinal and leg muscle." This apparatus does not require the user to perform a motion which will strengthen these muscles. No exercise resistance methods are employed.